President Donald Trump on Thursday morning ordered flags be flown at half-staff in reaction to Wednesday’s school shooting in Florida that claimed the lives of 17 people. Trump’s proclamation came shortly before he was expected to address the nation at 10 a.m. CT on Thursday (Feb. 15) about the shooting.

“Our nation grieves with those who have lost loved ones in the shooting at Marjory Stoneman Douglas High School in Parkland, Florida,” Trump wrote in the proclamation, which specified flags at all public buildings and grounds, military posts and naval vessels be flown at half-staff until sunset Monday (Feb. 19).

The order also includes flags at embassies, consular offices, military facilities and other federal installations abroad.

On Wednesday (Feb. 14), police said a 19-year-old former student at the Parkland high school, armed with an AR-15 assault rifle, opened fire on students and faculty. Seventeen people were killed and 14 injured, including five critically. Thursday morning, the alleged gunman was charged with 17 counts of premeditated murder.

Shortly after the shooting, Trump took to Twitter to express his “prayers and condolences” for victims of the shooting and their families. “No child, teacher or anyone else should ever feel unsafe in an American school,” he wrote.

In another Tweet, sent out Thursday morning, Trump noted that the 19-year-old alleged shooter had been seen as erratic and potentially dangerous by former classmates and teachers. “So many signs that the Florida shooter was mentally disturbed, even expelled from school for bad and erratic behavior,” Trump wrote. “Neighbors and classmates knew he was a big problem. Must always report such instances to authorities, again and again!”

My prayers and condolences to the families of the victims of the terrible Florida shooting. No child, teacher or anyone else should ever feel unsafe in an American school.

— Donald J. Trump (@realDonaldTrump) February 14, 2018

Just spoke to Governor Rick Scott. We are working closely with law enforcement on the terrible Florida school shooting.

— Donald J. Trump (@realDonaldTrump) February 14, 2018

So many signs that the Florida shooter was mentally disturbed, even expelled from school for bad and erratic behavior. Neighbors and classmates knew he was a big problem. Must always report such instances to authorities, again and again!